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Cheng L, Zhou Y, Zhang H, Xiao S, Li W, Chen W. The influence of the molecular chain length of PVA on the toughening mechanism of calcium silicate hydrates. Phys Chem Chem Phys 2024; 26:9399-9412. [PMID: 38444367 DOI: 10.1039/d3cp05000a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2024]
Abstract
In recent years, polymers have been demonstrated to effectively toughen cementitious materials. However, the mechanism of interaction between the polymers and C-S-H at the nanoscale remains unclear, and the quantitative impact of the polymer chain length on toughening effectiveness is lacking in research. This study employs molecular dynamics techniques to examine the impact of the polyvinyl alcohol (PVA) chain length on the tensile performance and toughening mechanism of C-S-H. The toughening effect in both the X and Z directions exhibits an initial enhancement followed by a decline with increasing chain length. The optimal degrees of polymerization are determined to be 8 and 12 in the X and Z directions, respectively, resulting in an improvement of fracture energy by 146.7% and 29.5%, respectively. During the stretching process along the X and Z axes, the chain length of PVA molecules significantly influences the variation in the number of Ca⋯O bonds in the system, leading to different stress responses. Additionally, PVA molecules form C-O-Si bonds with the silicate layers of C-S-H, bridging the adjacent layers in a left-right or up-down manner. The toughening effect of PVA on C-S-H depends on the behavior of PVA molecules with different chain lengths, and there exists an optimal range of chain length for PVA, enabling it to enhance structural uniformity and adjust its own conformation to absorb strain energy. When the length of PVA molecular chains is too short, it can easily cause stress concentration in the system and its connection with silicates is not significant. Conversely, when the length of PVA molecular chains is too long, the large molecular structure restricts its extension in the defects of C-S-H, and as the stretching progresses, PVA molecules break and form numerous small segments, thereby losing the advantage of the chain length. This study provides a theoretical basis for the ability of polymers to toughen cementitious materials.
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Affiliation(s)
- Luqing Cheng
- School of Materials Science and Engineering, Southeast University, Nanjing, Jiangsu 211189, China.
- State Key Laboratory of High Performance Civil Engineering Materials, Jiangsu Research Institute of Building Science Co., Nanjing 211103, China.
| | - Yang Zhou
- School of Materials Science and Engineering, Southeast University, Nanjing, Jiangsu 211189, China.
- State Key Laboratory of High Performance Civil Engineering Materials, Jiangsu Research Institute of Building Science Co., Nanjing 211103, China.
| | - Hao Zhang
- State Key Laboratory of High Performance Civil Engineering Materials, Jiangsu Research Institute of Building Science Co., Nanjing 211103, China.
| | - Shuai Xiao
- School of Materials Science and Engineering, Southeast University, Nanjing, Jiangsu 211189, China.
- State Key Laboratory of High Performance Civil Engineering Materials, Jiangsu Research Institute of Building Science Co., Nanjing 211103, China.
| | - Weihuan Li
- School of Materials Science and Engineering, Southeast University, Nanjing, Jiangsu 211189, China.
- State Key Laboratory of High Performance Civil Engineering Materials, Jiangsu Research Institute of Building Science Co., Nanjing 211103, China.
| | - Wentao Chen
- School of Materials Science and Engineering, Southeast University, Nanjing, Jiangsu 211189, China.
- State Key Laboratory of High Performance Civil Engineering Materials, Jiangsu Research Institute of Building Science Co., Nanjing 211103, China.
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2
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Mohtasham Moein M, Rahmati K, Saradar A, Moon J, Karakouzian M. A Critical Review Examining the Characteristics of Modified Concretes with Different Nanomaterials. MATERIALS (BASEL, SWITZERLAND) 2024; 17:409. [PMID: 38255577 PMCID: PMC10817359 DOI: 10.3390/ma17020409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Revised: 01/03/2024] [Accepted: 01/09/2024] [Indexed: 01/24/2024]
Abstract
The movement of the construction industry towards sustainable development has drawn attention to the revision of concrete. In addition to reducing pollution, the use of nano-materials should lead to the provision of higher quality concrete in terms of regulatory items (workability, resistance characteristics, durability characteristics, microstructure). The present study investigates 15 key characteristics of concrete modified with nano-CaCO3, nano-clay, nano-TiO2, and nano-SiO2. The results of the study showed that nanomaterials significantly have a positive effect on the hydration mechanism and the production of more C-S-H gel. The evaluation of resistance characteristics also indicates the promising results of these valuable materials. The durability characteristics of nano-containing concrete showed significant improvement despite high dispersion. Concrete in coastal areas (such as bridges or platforms), concrete exposed to radiation (such as hospitals), concrete exposed to impact load (such as nuclear power plants), and concrete containing recycled aggregate (such as bricks, tiles, ceramics) can be effectively improved by using nanomaterials. It is hoped that the current review paper can provide an effective image and idea for future applied studies by other researchers.
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Affiliation(s)
| | - Komeil Rahmati
- Department of Civil Engineering, Somesara Branch, Islamic Azad University, Somesara 4361947496, Iran;
| | - Ashkan Saradar
- Department of Civil Engineering, University of Guilan, Rasht 419961377, Iran
| | - Jaeyun Moon
- Department of Mechanical Engineering, University of Nevada, 4505 S Maryland Pkwy, Las Vegas, NV 89154, USA;
| | - Moses Karakouzian
- Department of Civil and Environmental Engineering and Construction, University of Nevada, Las Vegas, NV 89154, USA
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3
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Yang F, Cui Y, She A, Hai R, Zhu Z. Molecular Dynamics Simulation of Silane Inserted CSH Nanostructure. MATERIALS (BASEL, SWITZERLAND) 2023; 17:149. [PMID: 38204002 PMCID: PMC10780238 DOI: 10.3390/ma17010149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 12/21/2023] [Accepted: 12/25/2023] [Indexed: 01/12/2024]
Abstract
Herein, the toughening mechanism and effects of 3-(aminopropyl)triethoxysilane (3-APTES) intercalation in calcium-silicate-hydrate (CSH) structures were investigated through molecular dynamics simulations. CSH established a model using 11 Å-tobermorite to simulate the tensile properties, toughness, adsorption energy, average orientation displacement and radial distribution function of 3-APTES intercalation at different Ca/Si ratios under conditions of a CVFF force field, an NVT system, and 298 K temperature. Simulation results demonstrate that 3-APTES alters the fracture process of CSH and effectively enhances its tensile properties and toughness. The presence of 3-APTES molecules increases the energy required to destroy CSH, thereby increasing the adsorption energy of CSH crystals. Furthermore, 3-APTES molecules effectively increase the atom density within the CSH structure. As the Ca/Si ratio increases, Ca-O bond formation is enhanced, with noticeable aggregation occurring because of modification by 3-APTES within the CSH structure. This study found that 3-APTES organic compounds can effectively improve the tensile, toughness, adsorption and other properties of the CSH structure, and further improve the microstructure of CSH.
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Affiliation(s)
- Fei Yang
- School of Architectural and Civil Engineering, Zhongyuan University of Technology, Zhengzhou 450007, China; (Y.C.); (R.H.)
| | - Yangyang Cui
- School of Architectural and Civil Engineering, Zhongyuan University of Technology, Zhengzhou 450007, China; (Y.C.); (R.H.)
| | - Anming She
- Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education, School of Materials Science and Engineering, Tongji University, Shanghai 201804, China;
| | - Ran Hai
- School of Architectural and Civil Engineering, Zhongyuan University of Technology, Zhengzhou 450007, China; (Y.C.); (R.H.)
| | - Zheyu Zhu
- School of Materials Science and Engineering, Yancheng Institute of Technology, Yancheng 224051, China;
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4
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Casar Z, Mohamed AK, Bowen P, Scrivener K. Atomic-Level and Surface Structure of Calcium Silicate Hydrate Nanofoils. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2023; 127:18652-18661. [PMID: 37752905 PMCID: PMC10518866 DOI: 10.1021/acs.jpcc.3c03350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 08/29/2023] [Indexed: 09/28/2023]
Abstract
Deciphering the calcium silicate hydrate (C-S-H) surface is crucial for unraveling the mechanisms of cement hydration and property development. Experimental observations of C-S-H in cement systems suggest a surface termination which is fundamentally different from the silicate-terminated surface assumed in many atomistic level studies. Here, a new multiparameter approach to describing the (001) basal C-S-H surface is developed, which considers how the surface termination affects the overall properties (Ca/Si ratio, mean chain length, relative concentration of silanol and hydroxide groups). Contrary to current beliefs, it is concluded that the (001) C-S-H surface is dominantly calcium terminated. Finally, an adsorption mechanism for calcium and hydroxide ions is proposed, which is in agreement with the surface charge densities observed in previous studies.
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Affiliation(s)
- Ziga Casar
- Laboratory
of Construction Materials, Institut des Matériaux, Ecole Polytechnique Fédérale de Lausanne
(EPFL), CH-1015 Lausanne, Switzerland
| | - Aslam Kunhi Mohamed
- Institute
for Building Materials, Department of Civil, Environmental and Geomatic
Engineering, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Paul Bowen
- Laboratory
of Construction Materials, Institut des Matériaux, Ecole Polytechnique Fédérale de Lausanne
(EPFL), CH-1015 Lausanne, Switzerland
| | - Karen Scrivener
- Laboratory
of Construction Materials, Institut des Matériaux, Ecole Polytechnique Fédérale de Lausanne
(EPFL), CH-1015 Lausanne, Switzerland
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5
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Zhou Y, Xiao S, Cheng L, Chen Y, Tang J, She W. A toughening mechanism of the strain rate-optimal chain length on polymer-modified calcium silicate hydrates (CSH). Phys Chem Chem Phys 2023; 25:24097-24109. [PMID: 37655461 DOI: 10.1039/d3cp01743e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
Polymers are known to effectively improve the toughness of inorganic matrices; however, the mechanism at the molecular level is still unclear. In this study, we used molecular dynamics simulations to unravel the effects and mechanisms of different molecular chain lengths of polyacrylic acid (PAA) on toughening calcium silicate hydrate (CSH), which is the basic building block of cement-based materials. Our simulation results indicate that an optimal molecular chain length of polymers contributes to the largest toughening effect on the matrix, leading to up to 60.98% increase in fracture energy. During the uniaxial tensile tests along the x-axis and z-axis direction, the configuration evolution of the PAA molecule determines the toughening effect. As the polymer unfolds and its size matches the defects of CSH, the stress distribution of the system becomes more homogeneous, which favors an increase in toughness. Furthermore, based on our simulation results and a mathematical model, we propose a theory of "strain rate/optimal chain length". This theory suggests that the optimal toughening effect can be achieved when the molecular chain length of the organic component is 1.3-1.5 times the largest defect size of the inorganic matrix. This work provides molecular-scale insights into the toughening mechanisms of an organic/inorganic system and may have practical implications for improving the toughness of cement-based materials.
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Affiliation(s)
- Yang Zhou
- School of Materials Science and Engineering, Southeast University, Nanjing, Jiangsu 211189, China.
- State Key Laboratory of High Performance Civil Engineering Materials, Jiangsu Research Institute of Building Science Co, Nanjing 211103, China
| | - Shuai Xiao
- School of Materials Science and Engineering, Southeast University, Nanjing, Jiangsu 211189, China.
- State Key Laboratory of High Performance Civil Engineering Materials, Jiangsu Research Institute of Building Science Co, Nanjing 211103, China
| | - Luqing Cheng
- School of Materials Science and Engineering, Southeast University, Nanjing, Jiangsu 211189, China.
- State Key Laboratory of High Performance Civil Engineering Materials, Jiangsu Research Institute of Building Science Co, Nanjing 211103, China
| | - Yuan Chen
- School of Materials Science and Engineering, Southeast University, Nanjing, Jiangsu 211189, China.
- State Key Laboratory of High Performance Civil Engineering Materials, Jiangsu Research Institute of Building Science Co, Nanjing 211103, China
| | - JinHui Tang
- School of Materials Science and Engineering, Southeast University, Nanjing, Jiangsu 211189, China.
- State Key Laboratory of High Performance Civil Engineering Materials, Jiangsu Research Institute of Building Science Co, Nanjing 211103, China
| | - Wei She
- School of Materials Science and Engineering, Southeast University, Nanjing, Jiangsu 211189, China.
- State Key Laboratory of High Performance Civil Engineering Materials, Jiangsu Research Institute of Building Science Co, Nanjing 211103, China
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6
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Sun Z, Li X, Liu Q, Tang Q, Lin X, Fan X, Huang X, Gan M, Chen X, Ji Z. Recent Advances in Alkali-Activated Materials with Seawater and Sea Sand. MATERIALS (BASEL, SWITZERLAND) 2023; 16:ma16093571. [PMID: 37176453 PMCID: PMC10179923 DOI: 10.3390/ma16093571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 04/26/2023] [Accepted: 04/30/2023] [Indexed: 05/15/2023]
Abstract
The development of sustainable cementitious materials is essential and urgent for the construction industry. Benefiting from excellent engineering properties and a reduced greenhouse gas footprint, alkali-activated materials (AAM) are among the robust alternatives to Portland cement for civil infrastructure. Meanwhile, concrete production also accounts for around 20% of all industrial water consumption, and the global freshwater shortage is increasing. This review discusses recent investigations on seawater-mixed AAMs, including the effects of seawater on workability, reaction mechanism, shrinkage, short and long-term strength, binding of chloride and corrosion of steel reinforcement. Attention is also paid to the utilization of sea sand as aggregate, as well as discussions on the challenges and further research perspectives on the field application of AAMs with seawater and sea sand.
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Affiliation(s)
- Zengqing Sun
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Xiaoyu Li
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Qingsong Liu
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Qingyu Tang
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Xiaochen Lin
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment of the People's Republic of China, Nanjing 210042, China
| | - Xiaohui Fan
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Xiaoxian Huang
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Min Gan
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Xuling Chen
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Zhiyun Ji
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
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7
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Liu X, Bai X, Zhong W, Deng X, Liang T. Investigation for Carbonation Mechanism of Tobermorite 9 Å: A Combination of DFT and Ab Initio Molecular Dynamics Study. ADVANCED THEORY AND SIMULATIONS 2022. [DOI: 10.1002/adts.202200729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Xiaotong Liu
- School of Mechanics and Safety Engineering Zhengzhou University Zhengzhou 450001 China
| | - Xiaolin Bai
- School of Mechanics and Safety Engineering Zhengzhou University Zhengzhou 450001 China
| | - Wei Zhong
- School of Mechanics and Safety Engineering Zhengzhou University Zhengzhou 450001 China
| | - Xiangsheng Deng
- School of Mechanics and Safety Engineering Zhengzhou University Zhengzhou 450001 China
| | - Tianshui Liang
- School of Mechanics and Safety Engineering Zhengzhou University Zhengzhou 450001 China
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8
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Influence of initial tensile stress on mechanical properties of calcium silicate hydrate under various strain rates by molecular dynamics simulation. Chem Phys Lett 2022. [DOI: 10.1016/j.cplett.2022.140184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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9
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Chen Y, Chen M, Tong X, Wang S, Kang X. Molecular insights into the interactions between chloride liquids and C−S−H nanopore surfaces under electric field-induced transport. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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10
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Microstructure of CEM II/B-S Pastes Modified with Set Accelerating Admixtures. MATERIALS 2021; 14:ma14216300. [PMID: 34771826 PMCID: PMC8585294 DOI: 10.3390/ma14216300] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 10/18/2021] [Accepted: 10/18/2021] [Indexed: 11/17/2022]
Abstract
The presented paper aims to describe the influence of accelerating admixtures on the properties and microstructure of cement pastes and mortars. Blended slag cement CEM II/B-S containing two different clinkers (differing amounts of siliceous and aluminous phases) and four types of accelerators (calcium nitrate, sodium hydroxide, cement kiln dust, and crystal seeds) were used in research. Compressive strength tests (after 12, 24, 48 h of curing), Scanning Electron Microscope (SEM) observations together with an Energy Dispersive Spectroscopy (EDS) analysis, Mercury Intrusion Porosimetry (MIP) tests, and X-ray diffraction (XRD) analysis were conducted. Results have shown that SEM and EDS examination of the microstructure of cement pastes modified with accelerating admixtures at the observed points did not reveal differences that would be sufficient to explain the changes in compressive strength. Still, the increase in amorphous phase content indicates a faster hydration reaction rate for all pastes modified with accelerating admixture. It is backed up also by lower non-hydrated compounds content. All admixtures accelerate the hydration reaction of calcium silicate phases of cement, but only NaOH and cement kiln dust (CKD) influence the aluminate phase reaction rate. The pore volume is independent of the clinker type, while the pore size distribution is not.
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11
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Municipal Solid Waste Incineration Ash-Incorporated Concrete: One Step towards Environmental Justice. BUILDINGS 2021. [DOI: 10.3390/buildings11110495] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Municipal solid waste and cement manufacture are two sources of environmental justice issues in urban and suburban areas. Waste utilization is an attractive alternative to disposal for eliminating environmental injustice, reducing potential hazards, and improving urban sustainability. The re-use and recycling of municipal solid waste incineration (MSWI) ash in the construction industry has drawn significant attention. Incorporating MSWI ash in cement and concrete production is a potential path that mitigates the environmental justice issues in waste management and the construction industry. This paper presents a critical overview of the pretreatment methods that optimize MSWI ash utilization in cement/concrete and the influences of MSWI ash on the performance of cement/concrete. This review aims to elucidate the potential advantages and limitations associated with the use of MSWI ash for producing cement clinker, alternative binder (e.g., alkali-activated material), cement substitutes, and aggregates. A brief overview of the generation and characteristics of MSWI ash is reported, accompanied by identifying opportunities for the use of MSWI ash-incorporated products in industrial-scale applications and recognizing associated environmental justice implications.
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12
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Yadav A, Krishnan NMA. Role of steric repulsions on the precipitation kinetics and the structure of calcium-silicate-hydrate gels. SOFT MATTER 2021; 17:8902-8914. [PMID: 34545899 DOI: 10.1039/d1sm00838b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The microstructure and properties of calcium-silicate-hydrate (C-S-H) gels are largely controlled by the physicochemical environment during their precipitation. However, the role of the steric repulsive environment induced by the pore solution chemistry on the kinetics, structure, and properties of C-S-H gels remains unclear. Here, we develop two potential formalisms, namely sinusoidal and polynomial, to simulate the role of steric repulsions in C-S-H. The results show excellent agreement with experimental observations of precipitation kinetics and elastic properties. We demonstrate that the repulsive interactions result in delayed precipitation and percolation, and an open and branched microstructure. Interestingly, the elastic properties (which are equilibrium properties) are also significantly affected by these second-neighbor interactions. Overall, the present study demonstrates that the kinetics, structure, and equilibrium properties of colloidal gels are controlled by the steric repulsions induced by the chemical environment.
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Affiliation(s)
- Ashish Yadav
- Department of Civil Engineering, Indian Institute of Technology Delhi, New Delhi, India.
| | - N M Anoop Krishnan
- Department of Civil Engineering, Indian Institute of Technology Delhi, New Delhi, India.
- Department of Materials Science and Engineering, Indian Institute of Technology Delhi, New Delhi, India
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13
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Goyal A, Palaia I, Ioannidou K, Ulm FJ, van Damme H, Pellenq RJM, Trizac E, Del Gado E. The physics of cement cohesion. SCIENCE ADVANCES 2021; 7:7/32/eabg5882. [PMID: 34348896 PMCID: PMC8336951 DOI: 10.1126/sciadv.abg5882] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 06/17/2021] [Indexed: 06/13/2023]
Abstract
Cement is the most produced material in the world. A major player in greenhouse gas emissions, it is the main binding agent in concrete, providing a cohesive strength that rapidly increases during setting. Understanding how such cohesion emerges is a major obstacle to advances in cement science and technology. Here, we combine computational statistical mechanics and theory to demonstrate how cement cohesion arises from the organization of interlocked ions and water, progressively confined in nanoslits between charged surfaces of calcium-silicate-hydrates. Because of the water/ions interlocking, dielectric screening is drastically reduced and ionic correlations are proven notably stronger than previously thought, dictating the evolution of nanoscale interactions during cement hydration. By developing a quantitative analytical prediction of cement cohesion based on Coulombic forces, we reconcile a fundamental understanding of cement hydration with the fully atomistic description of the solid cement paste and open new paths for scientific design of construction materials.
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Affiliation(s)
- Abhay Goyal
- Department of Physics, Institute for Soft Matter Synthesis and Metrology, Georgetown University, Washington, DC 20057, USA.
| | - Ivan Palaia
- Université Paris-Saclay, CNRS, LPTMS, 91405 Orsay, France
- Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
| | - Katerina Ioannidou
- Laboratoire de Mécanique et Génie Civil, CNRS, Université de Montpellier, 34090 Montpellier, France
- Massachusetts Institute of Technology/CNRS/Aix-Marseille University Joint Laboratory, Cambridge, MA 02139, USA
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Franz-Josef Ulm
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Henri van Damme
- École Supérieure de Physique et Chimie Industrielle de la Ville de Paris, 10 rue Vauquelin, 75005 Paris, France
| | - Roland J-M Pellenq
- Massachusetts Institute of Technology/CNRS/Aix-Marseille University Joint Laboratory, Cambridge, MA 02139, USA
- Department of Physics, Georgetown University, Washington, DC 20057, USA
| | | | - Emanuela Del Gado
- Department of Physics, Institute for Soft Matter Synthesis and Metrology, Georgetown University, Washington, DC 20057, USA.
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An Overview on the Rheology, Mechanical Properties, Durability, 3D Printing, and Microstructural Performance of Nanomaterials in Cementitious Composites. MATERIALS 2021; 14:ma14112950. [PMID: 34070728 PMCID: PMC8198580 DOI: 10.3390/ma14112950] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 05/23/2021] [Accepted: 05/27/2021] [Indexed: 01/28/2023]
Abstract
The most active research area is nanotechnology in cementitious composites, which has a wide range of applications and has achieved popularity over the last three decades. Nanoparticles (NPs) have emerged as possible materials to be used in the field of civil engineering. Previous research has concentrated on evaluating the effect of different NPs in cementitious materials to alter material characteristics. In order to provide a broad understanding of how nanomaterials (NMs) can be used, this paper critically evaluates previous research on the influence of rheology, mechanical properties, durability, 3D printing, and microstructural performance on cementitious materials. The flow properties of fresh cementitious composites can be measured using rheology and slump. Mechanical properties such as compressive, flexural, and split tensile strength reveal hardened properties. The necessary tests for determining a NM’s durability in concrete are shrinkage, pore structure and porosity, and permeability. The advent of modern 3D printing technologies is suitable for structural printing, such as contour crafting and binder jetting. Three-dimensional (3D) printing has opened up new avenues for the building and construction industry to become more digital. Regardless of the material science, a range of problems must be tackled, including developing smart cementitious composites suitable for 3D structural printing. According to the scanning electron microscopy results, the addition of NMs to cementitious materials results in a denser and improved microstructure with more hydration products. This paper provides valuable information and details about the rheology, mechanical properties, durability, 3D printing, and microstructural performance of cementitious materials with NMs and encourages further research.
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15
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Structure, Fractality, Mechanics and Durability of Calcium Silicate Hydrates. FRACTAL AND FRACTIONAL 2021. [DOI: 10.3390/fractalfract5020047] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Cement-based materials are widely utilized in infrastructure. The main product of hydrated products of cement-based materials is calcium silicate hydrate (C-S-H) gels that are considered as the binding phase of cement paste. C-S-H gels in Portland cement paste account for 60–70% of hydrated products by volume, which has profound influence on the mechanical properties and durability of cement-based materials. The preparation method of C-S-H gels has been well documented, but the quality of the prepared C-S-H affects experimental results; therefore, this review studies the preparation method of C-S-H under different conditions and materials. The progress related to C-S-H microstructure is explored from the theoretical and computational point of view. The fractality of C-S-H is discussed. An evaluation of the mechanical properties of C-S-H has also been included in this review. Finally, there is a discussion of the durability of C-S-H, with special reference to the carbonization and chloride/sulfate attacks.
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16
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Abstract
Carbonation in cement binders has to be thoroughly understood because it affects phase assemblage, binder microstructure and durability performance of concretes. This is still not the case as the reaction products can be crystalline, nanocrystalline and amorphous. The characterisation of the last two types of components are quite challenging. Here, carbonation reactions have been studied in alite-, belite- and ye’elimite-containing pastes, in controlled conditions (3% CO2 and RH = 65%). Pair distribution function (PDF) jointly with Rietveld and thermal analyses have been applied to prove that ettringite decomposed to yield crystalline aragonite, bassanite and nano-gibbsite without any formation of amorphous calcium carbonate. The particle size of gibbsite under these conditions was found to be larger (~5 nm) than that coming from the direct hydration of ye’elimite with anhydrite (~3 nm). Moreover, the carbonation of mixtures of C-S-H gel and portlandite, from alite and belite hydration, led to the formation of the three crystalline CaCO3 polymorphs (calcite, aragonite and vaterite), amorphous silica gel and amorphous calcium carbonate. In addition to their PDF profiles, the thermal analyses traces are thoroughly analysed and discussed.
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17
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Kunhi Mohamed A, Moutzouri P, Berruyer P, Walder BJ, Siramanont J, Harris M, Negroni M, Galmarini SC, Parker SC, Scrivener KL, Emsley L, Bowen P. The Atomic-Level Structure of Cementitious Calcium Aluminate Silicate Hydrate. J Am Chem Soc 2020; 142:11060-11071. [PMID: 32406680 DOI: 10.1021/jacs.0c02988] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Despite use of blended cements containing significant amounts of aluminum for over 30 years, the structural nature of aluminum in the main hydration product, calcium aluminate silicate hydrate (C-A-S-H), remains elusive. Using first-principles calculations, we predict that aluminum is incorporated into the bridging sites of the linear silicate chains and that at high Ca:Si and H2O ratios, the stable coordination number of aluminum is six. Specifically, we predict that silicate-bridging [AlO2(OH)4]5- complexes are favored, stabilized by hydroxyl ligands and charge balancing calcium ions in the interlayer space. This structure is then confirmed experimentally by one- and two-dimensional dynamic nuclear polarization enhanced 27Al and 29Si solid-state NMR experiments. We notably assign a narrow 27Al NMR signal at 5 ppm to the silicate-bridging [AlO2(OH)4]5- sites and show that this signal correlates to 29Si NMR signals from silicates in C-A-S-H, conflicting with its conventional assignment to a "third aluminate hydrate" (TAH) phase. We therefore conclude that TAH does not exist. This resolves a long-standing dilemma about the location and nature of the six-fold-coordinated aluminum observed by 27Al NMR in C-A-S-H samples.
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Affiliation(s)
- Aslam Kunhi Mohamed
- Laboratory of Construction Materials, Institut des Matériaux, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.,Institute for Building Materials, Department of Civil, Environmental and Geomatic Engineering, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Pinelopi Moutzouri
- Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Pierrick Berruyer
- Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Brennan J Walder
- Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Jirawan Siramanont
- Laboratory of Construction Materials, Institut des Matériaux, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.,SCG CEMENT Co., Ltd., Saraburi 18260, Thailand
| | - Maya Harris
- Laboratory of Construction Materials, Institut des Matériaux, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Mattia Negroni
- Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Sandra C Galmarini
- Building Energy Materials and Components, EMPA, CH-8600 Dübendorf, Switzerland
| | - Stephen C Parker
- Computational Solid State Chemistry Group, Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K
| | - Karen L Scrivener
- Laboratory of Construction Materials, Institut des Matériaux, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Lyndon Emsley
- Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Paul Bowen
- Laboratory of Construction Materials, Institut des Matériaux, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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18
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Cuesta A, De la Torre ÁG, Santacruz I, Diaz A, Trtik P, Holler M, Lothenbach B, Aranda MAG. Quantitative disentanglement of nanocrystalline phases in cement pastes by synchrotron ptychographic X-ray tomography. IUCRJ 2019; 6:473-491. [PMID: 31098028 PMCID: PMC6503921 DOI: 10.1107/s2052252519003774] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 03/19/2019] [Indexed: 05/25/2023]
Abstract
Mortars and concretes are ubiquitous materials with very complex hierarchical microstructures. To fully understand their main properties and to decrease their CO2 footprint, a sound description of their spatially resolved mineralogy is necessary. Developing this knowledge is very challenging as about half of the volume of hydrated cement is a nanocrystalline component, calcium silicate hydrate (C-S-H) gel. Furthermore, other poorly crystalline phases (e.g. iron siliceous hydrogarnet or silica oxide) may coexist, which are even more difficult to characterize. Traditional spatially resolved techniques such as electron microscopy involve complex sample preparation steps that often lead to artefacts (e.g. dehydration and microstructural changes). Here, synchrotron ptychographic tomography has been used to obtain spatially resolved information on three unaltered representative samples: neat Portland paste, Portland-calcite and Portland-fly-ash blend pastes with a spatial resolution below 100 nm in samples with a volume of up to 5 × 104 µm3. For the neat Portland paste, the ptychotomographic study gave densities of 2.11 and 2.52 g cm-3 and a content of 41.1 and 6.4 vol% for nanocrystalline C-S-H gel and poorly crystalline iron siliceous hydrogarnet, respectively. Furthermore, the spatially resolved volumetric mass-density information has allowed characterization of inner-product and outer-product C-S-H gels. The average density of the inner-product C-S-H is smaller than that of the outer product and its variability is larger. Full characterization of the pastes, including segmentation of the different components, is reported and the contents are compared with the results obtained by thermodynamic modelling.
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Affiliation(s)
- Ana Cuesta
- Departamento de Química Inorgánica, Cristalografía y Mineralogía, Universidad de Málaga, 29071-Malaga, Spain
| | - Ángeles G. De la Torre
- Departamento de Química Inorgánica, Cristalografía y Mineralogía, Universidad de Málaga, 29071-Malaga, Spain
| | - Isabel Santacruz
- Departamento de Química Inorgánica, Cristalografía y Mineralogía, Universidad de Málaga, 29071-Malaga, Spain
| | - Ana Diaz
- Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Pavel Trtik
- Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
- Faculty of Civil Engineering, Czech Technical University in Prague, 166 29 Prague, Czech Republic
| | - Mirko Holler
- Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Barbara Lothenbach
- EMPA, Laboratory for Concrete and Construction Chemistry, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland
| | - Miguel A. G. Aranda
- Departamento de Química Inorgánica, Cristalografía y Mineralogía, Universidad de Málaga, 29071-Malaga, Spain
- ALBA Synchrotron, Carrer de la Llum 2-26, E-08290 Cerdanyola del Vallès, Barcelona, Spain
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19
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A Comparative Study of Experimental Configurations in Synchrotron Pair Distribution Function. MATERIALS 2019; 12:ma12081347. [PMID: 31027173 PMCID: PMC6515447 DOI: 10.3390/ma12081347] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 04/22/2019] [Accepted: 04/23/2019] [Indexed: 11/17/2022]
Abstract
The identification and quantification of amorphous components and nanocrystalline phases with very small crystal sizes, smaller than ~3 nm, within samples containing crystalline phases is very challenging. However, this is important as there are several types of systems that contain these matrices: building materials, glass-ceramics, some alloys, etc. The total scattering synchrotron pair distribution function (PDF) can be used to characterize the local atomic order of the nanocrystalline components and to carry out quantitative analyses in complex mixtures. Although the resolution in momentum transfer space has been widely discussed, the resolution in the interatomic distance space has not been discussed to the best of our knowledge. Here, we report synchrotron PDF data collected at three beamlines in different experimental configurations and X-ray detectors. We not only discuss the effect of the resolution in Q-space, Qmax ins of the recorded data and Qmax of the processed data, but we also discuss the resolution in the interatomic distance (real) space. A thorough study of single-phase crystalline nickel used as standard was carried out. Then, selected cement-related samples including anhydrous tricalcium and dicalcium silicates, and pastes derived from the hydration of tricalcium silicate and ye’elimite with bassanite were analyzed.
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20
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Prabhu A, Gimel JC, Ayuela A, Arrese-Igor S, Gaitero JJ, Dolado JS. A multi-scale approach for percolation transition and its application to cement setting. Sci Rep 2018; 8:15830. [PMID: 30361491 PMCID: PMC6202394 DOI: 10.1038/s41598-018-33918-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 09/28/2018] [Indexed: 11/10/2022] Open
Abstract
Shortly after mixing cement grains with water, a cementitious fluid paste is formed that immediately transforms into a solid form by a phenomenon known as setting. Setting actually corresponds to the percolation of emergent network structures consisting of dissolving cement grains glued together by nanoscale hydration products, mainly calcium-silicate-hydrates. As happens in many percolation phenomena problems, the theoretical identification of the percolation threshold (i.e. the cement setting) is still challenging, since the length scale where percolation becomes apparent (typically the length of the cement grains, microns) is many times larger than the nanoscale hydrates forming the growing spanning network. Up to now, the long-lasting gap of knowledge on the establishment of a seamless handshake between both scales has been an unsurmountable obstacle for the development of a predictive theory of setting. Herein we present a true multi-scale model which concurrently provides information at the scale of cement grains (microns) and at the scale of the nano-hydrates that emerge during cement hydration. A key feature of the model is the recognition of cement setting as an off-lattice bond percolation process between cement grains. Inasmuch as this is so, the macroscopic probability of forming bonds between cement grains can be statistically analysed in smaller local observation windows containing fewer cement grains, where the nucleation and growth of the nano-hydrates can be explicitly described using a kinetic Monte Carlo Nucleation and Growth model. The most striking result of the model is the finding that only a few links (~12%) between cement grains are needed to reach setting. This directly unveils the importance of explicitly including nano-texture on the description of setting and explains why so low amount of nano-hydrates is needed for forming a spanning network. From the simulations, it becomes evident that this low amount is least affected by processing variables like the water-to-cement ratio and the presence of large quantities of nonreactive fillers. These counter-intuitive predictions were verified by ex-professo experiments that we have carried out to check the validity of our model.
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Affiliation(s)
- Achutha Prabhu
- División de Construcción Sostenible, TECNALIA, Parque Tecnológico de Bizkaia, Astondo Bidea, Edificio 700, 48160, Derio, Spain.
| | - Jean-Christophe Gimel
- MINT, UNIV Angers, INSERM 1066, CNRS 6021, Université Bretagne Loire, IBS-CHU, 4 rue Larrey, 49933, Angers, France
| | - Andrés Ayuela
- Centro de Física de Materiales, Centro Mixto CSIC-UPV/EHU, Paseo Manuel Lardizabal 5, 20018, San Sebastián, Spain.,Donostia International Physics Center, Paseo Manuel Lardizabal 3, 20018, San Sebastián, Spain
| | - Silvia Arrese-Igor
- Centro de Física de Materiales, Centro Mixto CSIC-UPV/EHU, Paseo Manuel Lardizabal 5, 20018, San Sebastián, Spain
| | - Juan J Gaitero
- División de Construcción Sostenible, TECNALIA, Parque Tecnológico de Bizkaia, Astondo Bidea, Edificio 700, 48160, Derio, Spain.,MATCON, Associated Unit CSIC-TECNALIA, Parque Tecnológico de Bizkaia, Astondo Bidea, Edificio 700, 48160, Derio, Spain
| | - Jorge S Dolado
- Centro de Física de Materiales, Centro Mixto CSIC-UPV/EHU, Paseo Manuel Lardizabal 5, 20018, San Sebastián, Spain. .,Donostia International Physics Center, Paseo Manuel Lardizabal 3, 20018, San Sebastián, Spain. .,Faculty of Civil Engineering and Geosciences, Delft University of Technology, Stevinweg 1, 2628 CN, Delft, The Netherlands.
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21
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Abstract
The time-dependent response of structural materials dominates our aging infrastructure's life expectancy and has important resilience implications. For calcium-silicate-hydrates, the glue of cement, nanoscale mechanisms underlying time-dependent phenomena are complex and remain poorly understood. This complexity originates in part from the inherent difficulty in studying nanoscale longtime phenomena in atomistic simulations. Herein, we propose a three-staged incremental stress-marching technique to overcome such limitations. The first stage unravels a stretched exponential relaxation, which is ubiquitous in glassy systems. When fully relaxed, the material behaves viscoelastically upon further loading, which is described by the standard solid model. By progressively increasing the interlayer water, the time-dependent response of calcium-silicate-hydrates exhibits a transition from viscoelastic to logarithmic creep. These findings bridge the gap between atomistic simulations and nanomechanical experimental measurements and pave the way for the design of reduced aging construction materials and other disordered systems such as metallic and oxide glasses.
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22
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Synchrotron Radiation Pair Distribution Function Analysis of Gels in Cements. CRYSTALS 2017. [DOI: 10.3390/cryst7100317] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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23
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24
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Geng G, Myers RJ, Qomi MJA, Monteiro PJM. Densification of the interlayer spacing governs the nanomechanical properties of calcium-silicate-hydrate. Sci Rep 2017; 7:10986. [PMID: 28887517 PMCID: PMC5591233 DOI: 10.1038/s41598-017-11146-8] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 08/18/2017] [Indexed: 11/20/2022] Open
Abstract
Calciuam-silicate-hydrate (C-S-H) is the principal binding phase in modern concrete. Molecular simulations imply that its nanoscale stiffness is ‘defect-driven’, i.e., dominated by crystallographic defects such as bridging site vacancies in its silicate chains. However, experimental validation of this result is difficult due to the hierarchically porous nature of C-S-H down to nanometers. Here, we integrate high pressure X-ray diffraction and atomistic simulations to correlate the anisotropic deformation of nanocrystalline C-S-H to its atomic-scale structure, which is changed by varying the Ca-to-Si molar ratio. Contrary to the ‘defect-driven’ hypothesis, we clearly observe stiffening of C-S-H with increasing Ca/Si in the range 0.8 ≤ Ca/Si ≤ 1.3, despite increasing numbers of vacancies in its silicate chains. The deformation of these chains along the b-axis occurs mainly through tilting of the Si-O-Si dihedral angle rather than shortening of the Si-O bond, and consequently there is no correlation between the incompressibilities of the a- and b-axes and the Ca/Si. On the contrary, the intrinsic stiffness of C-S-H solid is inversely correlated with the thickness of its interlayer space. This work provides direct experimental evidence to conduct more realistic modelling of C-S-H-based cementitious material.
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Affiliation(s)
- Guoqing Geng
- Department of Civil and Environmental Engineering, University of California, Berkeley, California, 94720, United States.
| | - Rupert J Myers
- Department of Civil and Environmental Engineering, University of California, Berkeley, California, 94720, United States.,School of Forestry & Environmental Studies, Yale University, New Haven, Connecticut, 06511, United States
| | | | - Paulo J M Monteiro
- Department of Civil and Environmental Engineering, University of California, Berkeley, California, 94720, United States. .,Material Science Division, Lawrence Berkeley National Laboratory, Berkeley, California, 94720, United States.
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25
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Diffusive, Displacive Deformations and Local Phase Transformation Govern the Mechanics of Layered Crystals: The Case Study of Tobermorite. Sci Rep 2017; 7:5907. [PMID: 28725006 PMCID: PMC5517551 DOI: 10.1038/s41598-017-05115-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 06/01/2017] [Indexed: 11/24/2022] Open
Abstract
Understanding the deformation mechanisms underlying the mechanical behavior of materials is the key to fundamental and engineering advances in materials' performance. Herein, we focus on crystalline calcium-silicate-hydrates (C-S-H) as a model system with applications in cementitious materials, bone-tissue engineering, drug delivery and refractory materials, and use molecular dynamics simulation to investigate its loading geometry dependent mechanical properties. By comparing various conventional (e.g. shear, compression and tension) and nano-indentation loading geometries, our findings demonstrate that the former loading leads to size-independent mechanical properties while the latter results in size-dependent mechanical properties at the nanometer scales. We found three key mechanisms govern the deformation and thus mechanics of the layered C-S-H: diffusive-controlled and displacive-controlled deformation mechanisms, and strain gradient with local phase transformations. Together, these elaborately classified mechanisms provide deep fundamental understanding and new insights on the relationship between the macro-scale mechanical properties and underlying molecular deformations, providing new opportunities to control and tune the mechanics of layered crystals and other complex materials such as glassy C-S-H, natural composite structures, and manmade laminated structures.
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26
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de Araujo GLB, Benmore CJ, Byrn SR. Local Structure of Ion Pair Interaction in Lapatinib Amorphous Dispersions characterized by Synchrotron X-Ray diffraction and Pair Distribution Function Analysis. Sci Rep 2017; 7:46367. [PMID: 28397829 PMCID: PMC5387732 DOI: 10.1038/srep46367] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 03/15/2017] [Indexed: 01/21/2023] Open
Abstract
For many years, the idea of analyzing atom-atom contacts in amorphous drug-polymer systems has been of major interest, because this method has always had the potential to differentiate between amorphous systems with domains and amorphous systems which are molecular mixtures. In this study, local structure of ionic and noninonic interactions were studied by High-Energy X-ray Diffraction and Pair Distribution Function (PDF) analysis in amorphous solid dispersions of lapatinib in hypromellose phthalate (HPMCP) and hypromellose (HPMC-E3). The strategy of extracting lapatinib intermolecular drug interactions from the total PDF x-ray pattern was successfully applied allowing the detection of distinct nearest neighbor contacts for the HPMC-E3 rich preparations showing that lapatinib molecules do not cluster in the same way as observed in HPMC-P, where ionic interactions are present. Orientational correlations up to nearest neighbor molecules at about 4.3 Å were observed for polymer rich samples; both observations showed strong correlation to the stability of the systems. Finally, the superior physical stability of 1:3 LP:HPMCP was consistent with the absence of significant intermolecular interactions in (∆) in the range of 3.0 to 6.0 Å, which are attributed to C-C, C-N and C-O nearest neighbor contacts present in drug-drug interactions.
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Affiliation(s)
- Gabriel L B de Araujo
- Department of Pharmacy, Faculty of Pharmaceutical Sciences, University of Sao Paulo, Sao Paulo, SP, 05508-900, Brazil.,Department of Industrial and Physical Pharmacy, Purdue University, West Lafayette, Indiana, 47906, United States
| | - Chris J Benmore
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Illinois, 60439, United States
| | - Stephen R Byrn
- Department of Industrial and Physical Pharmacy, Purdue University, West Lafayette, Indiana, 47906, United States
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27
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Grangeon S, Fernandez-Martinez A, Baronnet A, Marty N, Poulain A, Elkaïm E, Roosz C, Gaboreau S, Henocq P, Claret F. Quantitative X-ray pair distribution function analysis of nanocrystalline calcium silicate hydrates: a contribution to the understanding of cement chemistry. J Appl Crystallogr 2017; 50:14-21. [PMID: 28190991 PMCID: PMC5294392 DOI: 10.1107/s1600576716017404] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 10/28/2016] [Indexed: 11/19/2022] Open
Abstract
Quantitative analysis of the X-ray pair distribution function collected on calcium silicate hydrates having Ca/Si ratios ranging between 0.57 and 1.47 was applied. With increasing Ca/Si ratio, Si bridging tetrahedra are omitted and Ca(OH)2 is detected at the highest ratios. The structural evolution of nanocrystalline calcium silicate hydrate (C–S–H) as a function of its calcium to silicon (Ca/Si) ratio has been probed using qualitative and quantitative X-ray atomic pair distribution function analysis of synchrotron X-ray scattering data. Whatever the Ca/Si ratio, the C–S–H structure is similar to that of tobermorite. When the Ca/Si ratio increases from ∼0.6 to ∼1.2, Si wollastonite-like chains progressively depolymerize through preferential omission of Si bridging tetrahedra. When the Ca/Si ratio approaches ∼1.5, nanosheets of portlandite are detected in samples aged for 1 d, while microcrystalline portlandite is detected in samples aged for 1 year. High-resolution transmission electron microscopy imaging shows that the tobermorite-like structure is maintained to Ca/Si > 3.
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Affiliation(s)
- Sylvain Grangeon
- D3E/SVP, BRGM (French Geological Survey) , 3 Avenue Claude Guillemin, Orléans, 45060, France
| | | | - Alain Baronnet
- CINaM UMR 7325, Université Aix-Marseille, Marseille, 13288, France; CINaM UMR 7325, CNRS, Marseille, 13288, France
| | - Nicolas Marty
- D3E/SVP, BRGM (French Geological Survey) , 3 Avenue Claude Guillemin, Orléans, 45060, France
| | - Agnieszka Poulain
- ESRF, The European Synchrotron , 71 Avenue des Martyrs, Grenoble, 38000, France
| | - Erik Elkaïm
- Synchrotron Soleil , L'Orme des Merisiers Saint-Aubin, Gif-sur-Yvette Cedex, BP 48 91192, France
| | - Cédric Roosz
- Scientific Division, Andra , 1-7 Rue Jean Monnet, Parc de la Croix Blanche, Chatenay-Malabry Cedex, 92298, France
| | - Stéphane Gaboreau
- D3E/SVP, BRGM (French Geological Survey) , 3 Avenue Claude Guillemin, Orléans, 45060, France
| | - Pierre Henocq
- Scientific Division, Andra , 1-7 Rue Jean Monnet, Parc de la Croix Blanche, Chatenay-Malabry Cedex, 92298, France
| | - Francis Claret
- D3E/SVP, BRGM (French Geological Survey) , 3 Avenue Claude Guillemin, Orléans, 45060, France
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28
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Özçelik VO, White CE. Nanoscale Charge-Balancing Mechanism in Alkali-Substituted Calcium-Silicate-Hydrate Gels. J Phys Chem Lett 2016; 7:5266-5272. [PMID: 27973859 DOI: 10.1021/acs.jpclett.6b02233] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Alkali-activated materials and related alternative cementitious systems are sustainable technologies that have the potential to substantially lower the CO2 emissions associated with the construction industry. However, these systems have augmented chemical compositions as compared to ordinary Portland cement (OPC), which may impact the evolution of the hydrate phases. In particular, calcium-silicate-hydrate (C-S-H) gel, the main hydrate phase in OPC, is likely to be altered at the atomic scale due to changes in the bulk chemical composition, specifically via the addition of alkalis (i.e., Na or K) and aluminum. Here, via density functional theory calculations, we reveal the presence of a charge balancing mechanism at the molecular level in C-S-H gel (as modeled using crystalline 14 Å tobermorite) when alkalis and aluminum atoms are introduced into the structure. Different structural representations are obtained depending on the level of substitution and the degree of charge balancing incorporated in the structures. The impact of these substitutional and charge balancing effects on the structures is assessed by analyzing the formation energies, local bonding environments, diffusion barriers and mechanical properties. The results of this computational study provide information on the phase stability of alkali/aluminum containing C-S-H gels, shedding light on the fundamental atomic level mechanisms that play a crucial role in these complex disordered materials.
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Affiliation(s)
- V Ongun Özçelik
- Andlinger Center for Energy and the Environment, and ‡Department of Civil and Environmental Engineering, Princeton University , Princeton, New Jersey 08544, United States
| | - Claire E White
- Andlinger Center for Energy and the Environment, and ‡Department of Civil and Environmental Engineering, Princeton University , Princeton, New Jersey 08544, United States
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29
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You W, Weng Y, Wang X, Zhuang Z, Yu Y. Synthesis and Adsorption Properties of Hierarchically Ordered Nanostructures Derived from Porous CaO Network. ACS APPLIED MATERIALS & INTERFACES 2016; 8:33656-33665. [PMID: 27704764 DOI: 10.1021/acsami.6b11633] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Using the porous framework of CaO as templates and reagents, we explored a surfactant-free and economical method for preparing calcium silicate hydrate (CSH) hierarchically ordered nanostructures. Incorporation of SiO2 nanoparticles into the CaO framework, followed by a reaction assisted by hydrothermal treatment, resulted in the formation of CSH with well-defined morphologies. The structural features of CSH were characterized by 3-D hierarchical networks, wherein nanofibers assembled to form nanosheets, and nanosheets assembled to form hierarchically ordered structures. Investigation of the crystal growth mechanism indicated that the key to forming the CSH ordered assembly structure was confining the Ca/Si ratio within a small range. Nonclassic oriented aggregation mechanism was used to describe the crystal growth of nanosheets, while the porous CaO framework served as template/reagents responsible for the formation of hierarchical structures. The resulting CSH adsorbent exhibited better performance in removing Pb(II) compared with other types of random CSH adsorbents. Additionally, the hierarchical structure of CSH provided more pores and active sites as support for other active functional materials such as zerovalent iron (Fe0). As-produced CSH@Fe nanocomposite with self-supported structures displayed high capacities for removal of Pb(II) after five adsorption-desorption cycles, and high capacities for other heavy metal ions (Cu2+, Cd2+, and Cr2O72-) and organic contaminants.
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Affiliation(s)
- Weijie You
- Key Laboratory of Eco-materials Advanced Technology (Fuzhou University), Fujian Province University , Fujian Province 350108, China
- College of Materials Science and Engineering, Fuzhou University , New Campus, Fujian Province 350108, China
| | - Yali Weng
- Key Laboratory of Eco-materials Advanced Technology (Fuzhou University), Fujian Province University , Fujian Province 350108, China
- College of Materials Science and Engineering, Fuzhou University , New Campus, Fujian Province 350108, China
| | - Xiu Wang
- Key Laboratory of Eco-materials Advanced Technology (Fuzhou University), Fujian Province University , Fujian Province 350108, China
- College of Materials Science and Engineering, Fuzhou University , New Campus, Fujian Province 350108, China
| | - Zanyong Zhuang
- Key Laboratory of Eco-materials Advanced Technology (Fuzhou University), Fujian Province University , Fujian Province 350108, China
- College of Materials Science and Engineering, Fuzhou University , New Campus, Fujian Province 350108, China
| | - Yan Yu
- Key Laboratory of Eco-materials Advanced Technology (Fuzhou University), Fujian Province University , Fujian Province 350108, China
- College of Materials Science and Engineering, Fuzhou University , New Campus, Fujian Province 350108, China
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30
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Yu Z, Zhou A, Lau D. Mesoscopic packing of disk-like building blocks in calcium silicate hydrate. Sci Rep 2016; 6:36967. [PMID: 27845376 PMCID: PMC5109495 DOI: 10.1038/srep36967] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 10/24/2016] [Indexed: 12/02/2022] Open
Abstract
At 100-nanometer length scale, the mesoscopic structure of calcium silicate hydrate (C-S-H) plays a critical role in determining the macroscopic material properties, such as porosity. In order to explore the mesoscopic structure of C-S-H, we employ two effective techniques, nanoindentation test and molecular dynamics simulation. Grid nanoindentation tests find different porosity of C-S-H in cement paste specimens prepared at varied water-to-cement (w/c) ratios. The w/c-ratio-induced porosity difference can be ascribed to the aspect ratio (diameter-to-thickness ratio) of disk-like C-S-H building blocks. The molecular dynamics simulation, with a mesoscopic C-S-H model, reveals 3 typical packing patterns and relates the packing density to the aspect ratio. Illustrated with disk-like C-S-H building blocks, this study provides a description of C-S-H structures in complement to spherical-particle C-S-H models at the sub-micron scale.
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Affiliation(s)
- Zechuan Yu
- Department of Architecture and Civil Engineering, City University of Hong Kong, Hong Kong, China
| | - Ao Zhou
- Department of Architecture and Civil Engineering, City University of Hong Kong, Hong Kong, China
| | - Denvid Lau
- Department of Architecture and Civil Engineering, City University of Hong Kong, Hong Kong, China.,Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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31
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Grangeon S, Claret F, Roosz C, Sato T, Gaboreau S, Linard Y. Structure of nanocrystalline calcium silicate hydrates: insights from X-ray diffraction, synchrotron X-ray absorption and nuclear magnetic resonance. J Appl Crystallogr 2016; 49:771-783. [PMID: 27275135 PMCID: PMC4886978 DOI: 10.1107/s1600576716003885] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 03/07/2016] [Indexed: 11/11/2022] Open
Abstract
The structure of nanocrystalline calcium silicate hydrates (C-S-H) having Ca/Si ratios ranging between 0.57 ± 0.05 and 1.47 ± 0.04 was studied using an electron probe micro-analyser, powder X-ray diffraction, 29Si magic angle spinning NMR, and Fourier-transform infrared and synchrotron X-ray absorption spectroscopies. All samples can be described as nanocrystalline and defective tobermorite. At low Ca/Si ratio, the Si chains are defect free and the Si Q3 and Q2 environments account, respectively, for up to 40.2 ± 1.5% and 55.6 ± 3.0% of the total Si, with part of the Q3 Si being attributable to remnants of the synthesis reactant. As the Ca/Si ratio increases up to 0.87 ± 0.02, the Si Q3 environment decreases down to 0 and is preferentially replaced by the Q2 environment, which reaches 87.9 ± 2.0%. At higher ratios, Q2 decreases down to 32.0 ± 7.6% for Ca/Si = 1.38 ± 0.03 and is replaced by the Q1 environment, which peaks at 68.1 ± 3.8%. The combination of X-ray diffraction and NMR allowed capturing the depolymerization of Si chains as well as a two-step variation in the layer-to-layer distance. This latter first increases from ∼11.3 Å (for samples having a Ca/Si ratio <∼0.6) up to 12.25 Å at Ca/Si = 0.87 ± 0.02, probably as a result of a weaker layer-to-layer connectivity, and then decreases down to 11 Å when the Ca/Si ratio reaches 1.38 ± 0.03. The decrease in layer-to-layer distance results from the incorporation of interlayer Ca that may form a Ca(OH)2-like structure, nanocrystalline and intermixed with C-S-H layers, at high Ca/Si ratios.
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Affiliation(s)
- Sylvain Grangeon
- D3E/SVP, BRGM (French Geological Survey) , 3 avenue Claude Guillemin, Orléans, 45060, France
| | - Francis Claret
- D3E/SVP, BRGM (French Geological Survey) , 3 avenue Claude Guillemin, Orléans, 45060, France
| | - Cédric Roosz
- D3E/SVP, BRGM (French Geological Survey), 3 avenue Claude Guillemin, Orléans, 45060, France; Scientific Division, Andra, 1-7 rue Jean Monnet, Parc de la Croix Blanche, Châtenay-Malabry, France
| | - Tsutomu Sato
- Laboratory of Environmental Geology, Research Group of Geoenvironmental/Engineering Division of Solid Waste, Resources and Geoenvironmental/Engineering Graduate School of Engineering, Hokkaido University , Kita 13 Nishi 8, Sapporo, Japan
| | - Stéphane Gaboreau
- D3E/SVP, BRGM (French Geological Survey) , 3 avenue Claude Guillemin, Orléans, 45060, France
| | - Yannick Linard
- Centre de Meuse/Haute Marne, Andra , Bure, 55290, France
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32
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Aranda MA. Recent studies of cements and concretes by synchrotron radiation crystallographic and cognate methods. CRYSTALLOGR REV 2015. [DOI: 10.1080/0889311x.2015.1070260] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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33
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Li H, Zhang LL, Yi Z, Fratini E, Baglioni P, Chen SH. Translational and rotational dynamics of water contained in aged Portland cement pastes studied by quasi-elastic neutron scattering. J Colloid Interface Sci 2015; 452:2-7. [PMID: 25898172 DOI: 10.1016/j.jcis.2015.04.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 04/03/2015] [Accepted: 04/03/2015] [Indexed: 10/23/2022]
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34
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Sangodkar RP, Smith BJ, Gajan D, Rossini AJ, Roberts LR, Funkhouser GP, Lesage A, Emsley L, Chmelka BF. Influences of Dilute Organic Adsorbates on the Hydration of Low-Surface-Area Silicates. J Am Chem Soc 2015; 137:8096-112. [DOI: 10.1021/jacs.5b00622] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Rahul P. Sangodkar
- Department
of Chemical Engineering, University of California, Santa Barbara, California 93106, United States
| | - Benjamin J. Smith
- Department
of Chemical Engineering, University of California, Santa Barbara, California 93106, United States
| | - David Gajan
- Centre
de RMN à Très Hauts Champs, Institut de Sciences Analytiques
(CNRS/ENS Lyon/UCB Lyon 1), Université de Lyon, 69100 Villeurbanne, France
| | - Aaron J. Rossini
- Centre
de RMN à Très Hauts Champs, Institut de Sciences Analytiques
(CNRS/ENS Lyon/UCB Lyon 1), Université de Lyon, 69100 Villeurbanne, France
| | - Lawrence R. Roberts
- Roberts Consulting Group, 44
Windsor Avenue, Acton, Massachusetts 01720, United States
| | - Gary P. Funkhouser
- Halliburton, 3000 North
Sam Houston Parkway East, Houston, Texas 77032, United States
| | - Anne Lesage
- Centre
de RMN à Très Hauts Champs, Institut de Sciences Analytiques
(CNRS/ENS Lyon/UCB Lyon 1), Université de Lyon, 69100 Villeurbanne, France
| | - Lyndon Emsley
- Centre
de RMN à Très Hauts Champs, Institut de Sciences Analytiques
(CNRS/ENS Lyon/UCB Lyon 1), Université de Lyon, 69100 Villeurbanne, France
- Institut
des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Bradley F. Chmelka
- Department
of Chemical Engineering, University of California, Santa Barbara, California 93106, United States
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35
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Bauchy M, Qomi MJA, Ulm FJ, Pellenq RJM. Order and disorder in calcium-silicate-hydrate. J Chem Phys 2015; 140:214503. [PMID: 24908022 DOI: 10.1063/1.4878656] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Despite advances in the characterization and modeling of cement hydrates, the atomic order in Calcium-Silicate-Hydrate (C-S-H), the binding phase of cement, remains an open question. Indeed, in contrast to the former crystalline model, recent molecular models suggest that the nanoscale structure of C-S-H is amorphous. To elucidate this issue, we analyzed the structure of a realistic simulated model of C-S-H, and compared the latter to crystalline tobermorite, a natural analogue of C-S-H, and to an artificial ideal glass. The results clearly indicate that C-S-H appears as amorphous, when averaged on all atoms. However, an analysis of the order around each atomic species reveals that its structure shows an intermediate degree of order, retaining some characteristics of the crystal while acquiring an overall glass-like disorder. Thanks to a detailed quantification of order and disorder, we show that, while C-S-H retains some signatures of a tobermorite-like layered structure, hydrated species are completely amorphous.
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Affiliation(s)
- M Bauchy
- Concrete Sustainability Hub, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| | - M J Abdolhosseini Qomi
- Concrete Sustainability Hub, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| | - F-J Ulm
- Concrete Sustainability Hub, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| | - R J-M Pellenq
- Concrete Sustainability Hub, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
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36
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Combinatorial molecular optimization of cement hydrates. Nat Commun 2014; 5:4960. [PMID: 25248305 PMCID: PMC4200522 DOI: 10.1038/ncomms5960] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Accepted: 08/12/2014] [Indexed: 12/24/2022] Open
Abstract
Despite its ubiquitous presence in the built environment, concrete’s molecular-level properties are only recently being explored using experimental and simulation studies. Increasing societal concerns about concrete’s environmental footprint have provided strong motivation to develop new concrete with greater specific stiffness or strength (for structures with less material). Herein, a combinatorial approach is described to optimize properties of cement hydrates. The method entails screening a computationally generated database of atomic structures of calcium-silicate-hydrate, the binding phase of concrete, against a set of three defect attributes: calcium-to-silicon ratio as compositional index and two correlation distances describing medium-range silicon-oxygen and calcium-oxygen environments. Although structural and mechanical properties correlate well with calcium-to-silicon ratio, the cross-correlation between all three defect attributes reveals an indentation modulus-to-hardness ratio extremum, analogous to identifying optimum network connectivity in glass rheology. We also comment on implications of the present findings for a novel route to optimize the nanoscale mechanical properties of cement hydrate. Concrete is a vital material in meeting present day construction demands. Here, the authors report a computational combinatorial approach to understand how molecular level characteristics influence the mechanical properties of cement hydrates, via screening against distinct defect types.
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37
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Ioannidou K, Pellenq RJM, Del Gado E. Controlling local packing and growth in calcium-silicate-hydrate gels. SOFT MATTER 2014; 10:1121-33. [PMID: 24652466 DOI: 10.1039/c3sm52232f] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We investigate the development of gels under out-of-equilibrium conditions, such as calcium-silicate-hydrate (C-S-H) gels that form during cement hydration and are the major factor responsible for cement mechanical strength. We propose a new model and numerical approach to follow the gel formation upon precipitation and aggregation of nano-scale colloidal hydrates, whose effective interactions are consistent with forces measured in experiments at fixed lime concentrations. We use Grand Canonical Monte Carlo to mimic precipitation events during Molecular Dynamics simulations, with their rate corresponding to the hydrate production rate set by the chemical environment. Our results display hydrate precipitation curves that indeed reproduce the acceleration and deceleration regime typically observed in experiments and we are able to correctly capture the effect of lime concentration on the hydration kinetics and the gel morphology. Our analysis of the evolution of the gel morphology indicates that the acceleration is related to the formation of an optimal local crystalline packing that allows for large, elongated aggregates to grow and that is controlled by the underlying thermodynamics. The defects produced during precipitation favor branching and gelation that end up controlling the deceleration. The effects on the mechanical properties of C-S-H gels are also discussed.
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Affiliation(s)
- Katerina Ioannidou
- ETH Zurich, Department of Civil, Environmental and Geomatic Engineering, CH-8093 Zurich, Switzerland.
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38
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Qomi MJA, Bauchy M, Ulm FJ, Pellenq RJM. Anomalous composition-dependent dynamics of nanoconfined water in the interlayer of disordered calcium-silicates. J Chem Phys 2014; 140:054515. [DOI: 10.1063/1.4864118] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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39
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Mishra RK, Fernández-Carrasco L, Flatt RJ, Heinz H. A force field for tricalcium aluminate to characterize surface properties, initial hydration, and organically modified interfaces in atomic resolution. Dalton Trans 2014; 43:10602-16. [DOI: 10.1039/c4dt00438h] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A force field for tricalcium aluminate is presented, validated, and applied to generate insight into surface forces, the hydration reaction, and molecular adsorption that remains elusive from experiment.
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Affiliation(s)
- Ratan K. Mishra
- Department of Civil
- Environmental and Geomatic Engineering
- ETH Zurich
- CH-8093 Zürich, Switzerland
| | - Lucia Fernández-Carrasco
- Department of Architectural Technology I
- Universitat Politècnica de Catalunya
- 08028 Barcelona, Spain
| | - Robert J. Flatt
- Department of Civil
- Environmental and Geomatic Engineering
- ETH Zurich
- CH-8093 Zürich, Switzerland
| | - Hendrik Heinz
- Department of Polymer Engineering
- University of Akron
- Akron, USA
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40
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Grangeon S, Claret F, Linard Y, Chiaberge C. X-ray diffraction: a powerful tool to probe and understand the structure of nanocrystalline calcium silicate hydrates. ACTA CRYSTALLOGRAPHICA SECTION B, STRUCTURAL SCIENCE, CRYSTAL ENGINEERING AND MATERIALS 2013; 69:465-473. [PMID: 24056355 PMCID: PMC3786629 DOI: 10.1107/s2052519213021155] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Accepted: 07/29/2013] [Indexed: 06/01/2023]
Abstract
X-ray diffraction (XRD) patterns were calculated and compared to literature data with the aim of investigating the crystal structure of nanocrystalline calcium silicate hydrates (C-S-H), the main binding phase in hydrated Portland cement pastes. Published XRD patterns from C-S-H of Ca/Si ratios ranging from ~ 0.6 to ~ 1.7 are fully compatible with nanocrystalline and turbostratic tobermorite. Even at a ratio close or slightly higher than that of jennite (Ca/Si = 1.5) this latter mineral, which is required in some models to describe the structure of C-S-H, is not detected in the experimental XRD patterns. The 001 basal reflection from C-S-H, positioned at ~ 13.5 Å when the C-S-H structural Ca/Si ratio is low (< 0.9), shifts towards smaller d values and sharpens with increasing Ca/Si ratio, to reach ~ 11.2 Å when the Ca/Si ratio is higher than 1.5. Calculations indicate that the sharpening of the 001 reflection may be related to a crystallite size along c* (i.e. a mean number of stacked layers) increasing with the C-S-H Ca/Si ratio. Such an increase would contribute to the observed shift of the 001 reflection, but fails to quantitatively explain it. It is proposed that the observed shift could result from interstratification of at least two tobermorite-like layers, one having a high and the other a low Ca/Si ratio with a basal spacing of 11.3 and 14 Å, respectively.
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41
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Wu J, Zhu YJ, Chen F. Ultrathin calcium silicate hydrate nanosheets with large specific surface areas: synthesis, crystallization, layered self-assembly and applications as excellent adsorbents for drug, protein, and metal ions. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2013; 9:2911-2925. [PMID: 23585365 DOI: 10.1002/smll.201300097] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Indexed: 06/02/2023]
Abstract
A simple and low-cost solution synthesis is reported for low-crystalline 1.4 nm tobermorite-like calcium silicate hydrate (CSH) ultrathin nanosheets with a thickness of ~2.8 nm and with a large specific surface area (SSA), via a reaction-rate-controlled precipitation process. The BET SSA of the CSH ultrathin nanosheets can reach as high as 505 m(2) g(-1) . The CSH ultrathin nanosheets have little cytotoxicity and can be converted to anhydrous calcium silicate (ACS) ultrathin nanosheets with a well preserved morphology via a heat treatment process. The crystallinity of CSH ultrathin nanosheets can be improved by solvothermal treatment in water/ethanol binary solvents or a single solvent of water, producing well-crystalline 1.1 nm tobermorite-like CSH nanobelts or nanosheets. CSH ultrathin nanosheets acting as building blocks can self-assemble into layered nanostructures via three different routes. The CSH ultrathin nanosheets are investigated as promising adsorbents for protein (hemoglobin, Hb), drug (ibuprofen, IBU), and metal ions (Cr(3+) , Ni(2+) , Cu(2+) , Zn(2+) , Cd(2+) , Pb(2+) ). The highest adsorbed percentages of Hb and IBU are found to be 83% and 94%, respectively. The highest adsorption capacities of Hb and IBU are found to be as high as 878 milligram Hb per gram CSH and 2.2 gram IBU per gram CSH, respectively. The ppm level metal ions can be totally adsorbed from aqueous solution in just a few minutes. Thus, the CSH ultrathin nanosheets are a promising candidate as excellent adsorbents in the biomedical field and for waste water treatment. Several empirical laws are summarized based on the adsorption profiles of Hb and IBU using CSH ultrathin nanosheets as the adsorbent. Furthermore, the ACS ultrathin nanosheets as adsorbents for Hb protein and IBU drug are investigated.
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Affiliation(s)
- Jin Wu
- State Key Laboratory of High Performance, Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, PR China, Tel.: +86-21-52412616; Fax: +86-21-52413122
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42
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Feng D, Xie N, Gong C, Leng Z, Xiao H, Li H, Shi X. Portland Cement Paste Modified by TiO2 Nanoparticles: A Microstructure Perspective. Ind Eng Chem Res 2013. [DOI: 10.1021/ie4011595] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
| | - Ning Xie
- Corrosion and
Sustainable Infrastructure
Laboratory, Western Transportation Institute and Civil Engineering
Department, P.O. Box 174250, College of Engineering, Montana State University, Bozeman, Montana 59717-4250,
United States
| | | | - Zhen Leng
- Department
of Civil and Environmental
Engineering, Hong Kong Polytechnic University, 11 Yuk Choi Road, Hung Hom, Hong Kong
| | | | | | - Xianming Shi
- Corrosion and
Sustainable Infrastructure
Laboratory, Western Transportation Institute and Civil Engineering
Department, P.O. Box 174250, College of Engineering, Montana State University, Bozeman, Montana 59717-4250,
United States
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Profeta A, Mannocci F, Foxton R, Watson T, Feitosa V, De Carlo B, Mongiorgi R, Valdré G, Sauro S. Experimental etch-and-rinse adhesives doped with bioactive calcium silicate-based micro-fillers to generate therapeutic resin–dentin interfaces. Dent Mater 2013; 29:729-41. [DOI: 10.1016/j.dental.2013.04.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Revised: 03/17/2013] [Accepted: 04/04/2013] [Indexed: 01/31/2023]
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44
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Li H, Fratini E, Chiang WS, Baglioni P, Mamontov E, Chen SH. Dynamic behavior of hydration water in calcium-silicate-hydrate gel: a quasielastic neutron scattering spectroscopy investigation. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2012; 86:061505. [PMID: 23367956 DOI: 10.1103/physreve.86.061505] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Indexed: 06/01/2023]
Abstract
The translational dynamics of hydration water confined in calcium-silicate-hydrate (C-S-H) gel was studied by quasielastic neutron scattering spectroscopy in the temperature range from 280 to 230 K. The stretch exponent β, the self-diffusion constant D, the average translational relaxation time {τ}, and the temperature dependence of confinement radius α extracted from the elastic fraction of immobile water molecules p(Q) were obtained from the analyses of the low-Q spectra according to the relaxing cage model. Measurements were made using C-S-H of three different water contents, 10%, 17%, and 30%. Among the three samples of C-S-H gel with different water contents, the values of β decrease with increasing water contents, while α increases. The values of D and {τ} are insensitive to temperature for the two lower water contents, as opposed to the 30% case where a slight variation is observed. The trend for violation of the Stokes-Einstein relation is only visible in the case of 30% water content.
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Affiliation(s)
- Hua Li
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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45
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Abstract
This paper summarizes the scientific trends associated with the rapid development of the technique of high-energy X-ray diffraction over the past decade pertaining to the field of liquids, glasses, and amorphous materials. The measurement of high-quality X-ray structure factors out to large momentum transfers leads to high-resolution pair distribution functions which can be directly compared to theory or combined with data from other experimental techniques. The advantages of combining highly penetrating radiation with low angle scattering are outlined together with the data analysis procedure and formalism. Also included are advances in high-energy synchrotron beamline instrumentation, sample environment equipment, and an overview of the role of simulation and modeling for interpreting data from disordered materials. Several examples of recent trends in glass and liquid research are described. Finally, directions for future research are considered within the context of past and current developments in the field.
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Affiliation(s)
- C. J. Benmore
- Department of Physics, Arizona State University, Tempe, AZ 85287-1604, USA
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46
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Masoero E, Del Gado E, Pellenq RJM, Ulm FJ, Yip S. Nanostructure and nanomechanics of cement: polydisperse colloidal packing. PHYSICAL REVIEW LETTERS 2012; 109:155503. [PMID: 23102331 DOI: 10.1103/physrevlett.109.155503] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Revised: 03/23/2012] [Indexed: 06/01/2023]
Abstract
Cement setting and cohesion are governed by the precipitation and growth of calcium-silicate-hydrate, through a complex evolution of microstructure. A colloidal model to describe nucleation, packing, and rigidity of calcium-silicate-hydrate aggregates is proposed. Polydispersity and particle size dependent cohesion strength combine to produce a spectrum of packing fractions and of corresponding elastic properties that can be tested against nanoindentation experiments. Implications regarding plastic deformations and reconciling current structural characterizations are discussed.
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Affiliation(s)
- E Masoero
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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47
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Manzano H, Enyashin AN, Dolado JS, Ayuela A, Frenzel J, Seifert G. Do cement nanotubes exist? ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2012; 24:3239-3245. [PMID: 22589176 DOI: 10.1002/adma.201103704] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Revised: 02/27/2012] [Indexed: 05/31/2023]
Abstract
Using atomistic simulations, this work indicates that cement nanotubes can exist. The chemically compatible nanotubes are constructed from the two main minerals in ordinary Portland cement pastes, namely calcium hydroxide and a calcium silicate hydrate called tobermorite. These results show that such nanotubes are stable and have outstanding mechanical properties, unique characteristics that make them ideally suitable for nanoscale reinforcements of cements.
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Affiliation(s)
- H Manzano
- Molecular Spectroscopy Laboratory, Department of Physical Chemistry, University of the Basque Country UPV/EHU, BILBAO, Spain
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48
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Quantitative evaluation by glucose diffusion of microleakage in aged calcium silicate-based open-sandwich restorations. Int J Dent 2011; 2012:105863. [PMID: 22194747 PMCID: PMC3238369 DOI: 10.1155/2012/105863] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Revised: 10/11/2011] [Accepted: 10/13/2011] [Indexed: 11/17/2022] Open
Abstract
This study compared the in vitro marginal integrity of open-sandwich restorations based on aged calcium silicate cement versus resin-modified glass ionomer cement. Class II cavities were prepared on 30 extracted human third molars. These teeth were randomly assigned to two groups (n = 10) to compare a new hydraulic calcium silicate cement designed for restorative dentistry (Biodentine, Septodont, Saint Maur des Fossés, France) with a resin-modified glass ionomer cement (Ionolux, Voco, Cuxhaven, Germany) in open-sandwich restorations covered with a light-cured composite. Positive (n = 5) and negative (n = 5) controls were included. The teeth simultaneously underwent thermocycling and mechanocycling using a fatigue cycling machine (1,440 cycles, 5-55°C; 86,400 cycles, 50 N/cm(2)). The specimens were then stored in phosphate-buffered saline to simulate aging. After 1 year, the teeth were submitted to glucose diffusion, and the resulting data were analyzed with a nonparametric Mann-Whitney test. The Biodentine group and the Ionolux group presented glucose concentrations of 0.074 ± 0.035 g/L and 0.080 ± 0.032 g/L, respectively. No statistically significant differences were detected between the two groups. Therefore, the calcium silicate-based material performs as well as the resin-modified glass ionomer cement in open-sandwich restorations.
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49
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Origins of saccharide-dependent hydration at aluminate, silicate, and aluminosilicate surfaces. Proc Natl Acad Sci U S A 2011; 108:8949-54. [PMID: 21562207 DOI: 10.1073/pnas.1104526108] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Sugar molecules adsorbed at hydrated inorganic oxide surfaces occur ubiquitously in nature and in technologically important materials and processes, including marine biomineralization, cement hydration, corrosion inhibition, bioadhesion, and bone resorption. Among these examples, surprisingly diverse hydration behaviors are observed for oxides in the presence of saccharides with closely related compositions and structures. Glucose, sucrose, and maltodextrin, for example, exhibit significant differences in their adsorption selectivities and alkaline reaction properties on hydrating aluminate, silicate, and aluminosilicate surfaces that are shown to be due to the molecular architectures of the saccharides. Solid-state (1)H, (13)C, (29)Si, and (27)Al nuclear magnetic resonance (NMR) spectroscopy measurements, including at very high magnetic fields (19 T), distinguish and quantify the different molecular species, their chemical transformations, and their site-specific adsorption on different aluminate and silicate moieties. Two-dimensional NMR results establish nonselective adsorption of glucose degradation products containing carboxylic acids on both hydrated silicates and aluminates. In contrast, sucrose adsorbs intact at hydrated silicate sites and selectively at anhydrous, but not hydrated, aluminate moieties. Quantitative surface force measurements establish that sucrose adsorbs strongly as multilayers on hydrated aluminosilicate surfaces. The molecular structures and physicochemical properties of the saccharides and their degradation species correlate well with their adsorption behaviors. The results explain the dramatically different effects that small amounts of different types of sugars have on the rates at which aluminate, silicate, and aluminosilicate species hydrate, with important implications for diverse materials and applications.
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Cerveny S, Arrese-Igor S, Dolado JS, Gaitero JJ, Alegría A, Colmenero J. Effect of hydration on the dielectric properties of C-S-H gel. J Chem Phys 2011; 134:034509. [PMID: 21261370 DOI: 10.1063/1.3521481] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The behavior of water dynamics confined in hydrated calcium silicate hydrate (C-S-H) gel has been investigated using broadband dielectric spectroscopy (BDS; 10(-2)-10(6) Hz) in the low-temperature range (110-250 K). Different water contents in C-S-H gel were explored (from 6 to 15 wt%) where water remains amorphous for all the studied temperatures. Three relaxation processes were found by BDS (labeled 1 to 3 from the fastest to the slowest), two of them reported here for the first time. We show that a strong change in the dielectric relaxation of C-S-H gel occurs with increasing hydration, especially at a hydration level in which a monolayer of water around the basic units of cement materials is predicted by different structural models. Below this hydration level both processes 2 and 3 have an Arrhenius temperature dependence. However, at higher hydration level, a non-Arrhenius behavior temperature dependence for process 3 over the whole accessible temperature range and, a crossover from low-temperature Arrhenius to high-temperature non-Arrhenius behavior for process 2 are observed. Characteristics of these processes will be discussed in this work.
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Affiliation(s)
- Silvina Cerveny
- Centro de Fisica de Materiales (CSIC, UPV∕EHU), Paseo Manuel de Lardizabal 5, 20018, San Sebastián, Spain.
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